package 测试常量; public class Test { public static void main(String[] args){ String s1 = “hello world”; String s2 = “hello world”; System.out.println(s1==s2); String s4 = new String(“你好”); String s3 = “你好”; System.out.println(s3==s4); Integer i1 = 10; Integer i2 = 10; System.out.println(i1 == i2); Integer i3 = 2000; Integer i4 = 2000; System.out.println(i3 == i4); Integer i5 = new Integer(10); Integer i6 = new Integer(10); System.out.println(i5 == i6); int i7 = 2000; int i8 = 2000; System.out.println(i7 == i8); Double f1 = new Double(1.01); Double f2 = new Double(1.01); System.out.println(f1 == f2); Double f3 = 1000.01; Double f4 = 1000.01; System.out.println(f3 == f4); double f5 = 1000.01; double f6 = 1000.01; System.out.println(f5 == f6); } }
输出结果是 true false true false false true false false true